Understanding the mechanism of dissolution of UO₂ in nitric acid is important for designing a continuous dissolution system for the reaction. Knowledge of the composition of the NO_X gas evolved during the course of the reaction is imperative for this understanding as it strongly influences the reaction mechanism. In this work, the profiles of the composition of NO_X gas evolved and the ratio of moles of acid consumed per mole of uranium dissolved during the dissolution of UO₂ pellets in nitric acid have been determined as a function of acidity. The predominant stoichiometric reaction by which UO₂ dissolves at every point of the reaction was clearly identified thereby improving the understanding of its mechanism and facilitates better control over the overall reprocessing process flowsheet.

理解UO ₂在硝酸中的溶解机理对于设计反应的连续溶解系统很重要。对于这种理解，当务之急是了解反应过程中释放出的NO _X气体的组成，因为它会严重影响反应机理。在这项工作中，已经确定了NO _X气体组成的分布图以及在UO ₂颗粒在硝酸中溶解期间每摩尔溶解的铀消耗的酸的摩尔比与酸度的关系。UO ₂的主要化学计量反应 可以清楚地识别出反应中每个点的溶解物，从而增进了对其机理的理解，并有助于更好地控制整个后处理流程。